This is why we need to be prepared for our class before the first time we see them. If possible go over your roll sheet and check up to see how diversfified your class is going to be. Most of this information is available if you know where to look and spend the time to look for it. You can also take notes during the early part of the class to help you plan future classes. You must be ready to make minor changes in your lesson plan if necessary to see that it fits the class. Remember they are there to learn so be ready to make adjustments if necessary. Having been a professional soccer coach, I know I couldn't do a shooting drill if my goalkeepers were out injured.